Continuous efforts have been made for the production of target products, such as amino acids or useful materials which can be used for various purposes including feeds, pharmaceutical drugs, foods, etc., at high titer using microorganisms (Korean Patent No. 10-0924065). As one of such methods, there is a method for inducing overexpression of a target gene in a microorganism, and a high-efficiency gene expression system is necessary for this purpose. Since promoters are one of the factors which are significantly involved in gene expression systems, development of a useful promoter is essential.
E. coli-derived tac promoter is widely-known as a strong promoter. In the case of the Coryne-form microorganism, strong promoters have been developed by modifying the promoters of self-genes (Gene, 102, 93-98, 1991; Microbiology, 142, 1297-1309, 1996). For example, in the cases of promoters derived from Corynebacterium ammoniagenesis, it is disclosed that there is about 10% improvement compared to that of the tac promoter reported in E. coli (Biotechnol. Lett. 25, 1311-1316, 2003). Additionally, as strong promoters derived from Corynebacterium ammoniagenesis, Pcj1 to Pcj7 promoters with various strengths were developed and they have strong promoter activities with at least 10-fold higher than that of tac promoter (Korean Patent No. 10-0620092). Additionally, the Po2 promoter, which was synthesized from Corynebacterium glutamicum to have a strong promoter activity, was developed (Korean Patent No. 10-1632642). However, there is still a need for the development of a promoter, since a system which exhibits high expression efficiency in Corynebacterium compared to the gene expression system of E. coli is needed.
Under the circumstances, the present inventors have made many efforts to discover promoters that can strongly induce gene expression in a microorganism of the genus Corynebacterium. As a result, they have developed a novel synthesized promoter of the present disclosure and confirmed that the promoter has a higher expression activity compared to those of the known promoters, thereby completing the present disclosure.